Pas de Deux
by bravevulnerability
Summary: 'His daughter is hopelessly smitten with her dance teacher, already attached, and she isn't the only one.' After enrolling Alexis in dance classes, Castle meets her talented instructor, Kate Beckett. AU. Three shot. For Alex.
1. Chapter 1

**A/N: For Alex - Happy Birthday!**

* * *

 _pas de deux - a dance for two_

* * *

The dance studio isn't locked, so Castle doesn't hesitate to enter. He's late, for the second time in three weeks, but the music is still blaring when he steps inside, still filling the small building with the pound of a fast paced, pop song. He assumes the teacher he met with briefly on Alexis's first day of class is just finishing up, but as he steps in closer, up to the glass door that separates the dance studio from the waiting area and changing rooms, he only sees two people on the floor.

His daughter and the beautiful woman she gushes about every Wednesday after he picks her up.

Castle practically presses his face to the glass barrier of the door, watching the tall brunette and his pint sized Alexis dancing in rhythm, nailing perfect leaps and turns with a sharp precision he's never witnessed until now. The style isn't exactly ballet - he supposes, because really, he doesn't know the first thing about dancing - but it's breathtaking. They both are.

"Tighten up on the turns," he hears the older woman instruct, her voice loud enough to be heard over the music, but not intimidating, not like he had feared when he had signed his daughter up for the classes she had begged for.

Alexis was still in her shy phase, always somewhat timid around others, especially those of authority, but she doesn't flinch at the command from this teacher, her expression remaining determined but calm as she follows the older woman's words, spinning at her side in unison as the song comes to a slow, dwindling towards completion.

"Keep those toes pointed, left knee bent," Kate Beckett calls out, all the while keeping her own movements precise but effortless, fluid as her body twists, gliding towards the mirror on harshly pointed toes.

The two of them come to a stop before the wall of mirrors lining the front of the room, Beckett continuing to coach, her voice growing softer through the fade of the music, and he studies his daughter, taking each gentle critique without a moment of hesitation, composing her face in an expression of serenity that matches her teacher's, as if playing a character in a story.

Maybe Alexis inherited some of his mother's acting skills after all, because whatever story his daughter and her instructor are telling through their actions, through their impressive jumps and striking pirouettes, he wants to know the meaning behind it.

The two hold the pose for a handful of seconds once silence has returned to the room, but as soon as Kate Beckett breaks her stance of stoicism, Alexis does too, a smile breaking out over her sweat glistened face, and then his daughter is throwing her arms around her teacher's waist, squealing in delight.

"I finally made it through without a single mistake!" Alexis exclaims, beaming up at her newfound mentor, a woman who's grinning down at her with matching excitement and a hint of pride, and if he thought Kate Beckett was gorgeous when she danced, he hadn't been at all prepared for the beauty of her smile.

"You did! I'm pretty sure you did better than me," Beckett tells her, patting her shoulder, causing Alexis to abruptly release Kate from the hug she had engulfed her in, the tinge of embarrassment turning the porcelain skin of his daughter's neck a subtle pink.

Alexis craved a reliable female figure in her life, he knew that, and he also knew that she had begun looking up to her dance teacher in a way that worried him. Because any woman Alexis had ever held in high regard in her short life had let her down, and while he didn't exactly know Kate Beckett, could never predict how she would handle such a role of admiration in his daughter's life, history had him anxious.

He was just so tired of seeing his baby bird disappointed.

"No way, no one's better than you, Ms. Beckett," Alexis chirps with a dismissive wave of her hand. "Do you think you could start teaching me a new routine soon?"

"Sure, but that doesn't mean we stop working on this one," Beckett answers, lifting her leg behind her and snagging the slim bone of her ankle, tugging her calf upwards in a stretch and nodding towards the ballet bar lining the back wall. "Now go relax those muscles."

Castle takes that as his moment, easing open the door and entering with a slow clap that startles them both. Oops.

"Amazing performance," he adds, noticing that this time, it's Ms. Beckett whose skin goes a little flush.

"Dad," Alexis groans, covering her face with her hands. "You're not supposed to watch us dance."

Ms. Beckett chuckles and nudges Alexis towards the bar. "Don't be embarrassed, Alexis. I'm sure your performance blew your dad away."

And it's the way the woman shoots him a threatening glare over his daughter's fiery red bun that has hope flaring in his gut. He's used that same look many times with Meredith, with Gina - the warning of _don't you dare hurt her feelings_.

Kate Beckett is protective of his child, she cares about her, and he has to admit, he was a bit smitten upon meeting her, but now he's entranced.

"Are you kidding? Pumpkin, you were incredible," Rick praises, bending to his knees as Alexis's eyes shine sapphire with elation and wow, he hasn't seen his daughter this happy in a while.

"She's also top of my class," Kate chimes in with a quirk of her lips. "Alexis has the kind of dedication a dancer needs to succeed and I'm lucky to have her."

The smile that claims his mouth has his cheeks aching while Alexis's turn the color of her hair at the commendation of her teacher, and as Castle tugs his daughter into a quick embrace, he offers Kate a wink of appreciation.

But the dance teacher merely nods before turning on silent feet and padding towards the small desk in the far corner of the room that holds what he assumes are her belongings, notes for the class, and a massive stereo. He tries very hard not to follow her retreating figure with his gaze, the lithe line of her body, the sinewy curves of her-

"Daddy," Alexis whispers, trapping his head between her tiny palms but there's a tiny grin playing on her lips. "It's not polite to stare."

* * *

Kate had met Mr. Castle once, during the early days of registration when he had strolled into her studio along with a slew of other eager parents, and signed his bashful little girl up for her weekly classes. Alexis had no history in dance, was not an avid trainee starving to perfect the sport and take her skill into the rigorous world of dance competition as most of her peers were. She was just a nine year old girl who had hoped to learn to dance like the beautiful ballerinas she had seen perform at her most recent viewing of the Nutcracker last Christmas.

But Alexis was a natural, possessing grace and coordination that is complicated for most girls her age to master, picking up on Kate's teachings on the first try, mimicking Beckett's movements with ease. The other girls tended to pick on her out of jealousy, her hourly sessions sometimes turning into a competition Kate did her best to dispel the moment she noticed. But it was after class, while they were waiting for her father, that Alexis seemed to have the most fun.

Richard Castle had been her favorite author for years, ever since her mom died and her father found comfort in a bottle while she found healing in her passion. Castle's words had kept her company during her years at Juilliard, soothing her shredded heart on the nights she yearned for her mother, reminding her that sometimes the good guys could still win.

Her first meeting with him had been brief, a whirlwind of polite smiles and talk of his daughter while they worked through the registration process in minutes. But now, after three months of training Alexis, she has learned that her favorite author is rarely on time.

Alexis always arrives before class starts, always early with time to spare that she spends stretching and warming up, but there have been far too many instances to count where Castle has returned late, sometimes by a few minutes, sometimes by a half hour.

In the beginning, it had irritated her, not because she minded - Alexis's was the last class of the day and at 5 p.m., she was in no hurry to get home to her empty apartment - but because it spoke of ill parenting. Alexis had assured her quickly, though, of how untrue that was when Kate voiced a soft spoken concern for the girl.

"Daddy just gets lost in his writing sometimes," his daughter had explained on the third occurrence of his overdue pickup habits. "He never means to do it, and he never forgets about the important things, like school or dinners. And he always takes a break from writing to play ballet with me if I ask him to."

She had helplessly softened at that, but it still didn't make her immune to the sight of his daughter sitting alone in the waiting area. So that same evening, Kate had called her back into the studio, taught her a routine she had choreographed for herself alone.

She had never intended to share the dance with anyone else, the meaning behind the steps personal, but with Alexis, she hadn't hesitated, and of course, the girl had been able to absorb the composition of movements, the underlying emotion effortlessly.

Alexis was everything she had been looking for in a student since she had opened her studio and over time, over dances and secret talks about absent mothers, she had formed a tenderness for her.

"Hey."

Kate glances over her shoulder to see Richard Castle approaching her desk, but doesn't pause in her unnecessary organization of CDs to give him her attention.

"Yes, Mr. Castle?"

"While Alexis is changing, I just wanted to thank you," he begins, standing close enough to allow her a breath of his aftershave, but far enough to respect her personal space.

"Oh, no you don't have to," Beckett assures him. "What she did was all a product of her own practice and dedication, she's-"

"Not just for that," Castle murmurs and Kate sets down the stack of instrumentals to face him, reading words unspoken in piercing blue eyes that are a shade sharper than his daughter's. "She just - she looks up to you, and she hasn't had many people to admire before."

Kate nods her understanding. She knows bits and pieces about that, about the disappointment of a mother that Alexis sometimes carries onto the dance floor with her.

"She's a good kid. Talented."

"I know she is," Castle smiles, the adoration illuminating his entire face, causing an inappropriate flare of heat to bloom within her abdomen. "But sometimes I don't think she does. So thank you for helping her see it."

"Dad," Alexis calls from the waiting area, her dance bag slung over her shoulder.

"It was nice to meet you again, Ms. Beckett," Castle offers, extending his hand, and Kate slips her fingers into the welcoming embrace of his palm before she can think better of it, bites her lip at the spread of warmth that consumes her hand, the soft hum of electricity trailing up the length of her arm.

"Likewise," she murmurs, withdrawing her hand and curling it around the edge of her desk, the worn hardwood cool in contrast. "And you can call me Kate."

His smile brightens. "Kate. I'll see you."

"See you," she nods, resisting the childish urge to twirl her finger through the stray strand of hair dangling free from the confines of her bun.

"Bye, Miss Beckett," Alexis calls over her shoulder once her father has joined her, waving as they move towards the door, and Kate waves back, though the sway of her hand falters for a split second when Castle snags her gaze on the way out onto the street.

She releases a deep breath once they're gone and she's left alone in the solitude of an empty studio. Her hand is still tingling, that strange sense of electricity on the tips of her fingers from his touch, and Kate shakes her head at the nonsense of it.

She's always had a silly crush on him, always spent a moment too long staring fondly at the picture on the back of his book jackets. She's just a little smitten with him, with the author who unknowingly helped her through hard times and the father who beams with pride for his daughter - that's all.

That _has_ to be all.

Kate turns the stereo back on, cranks the music up a notch too loud, and forces herself to stop thinking about Richard Castle and concentrate on the lyrical she'll be teaching the girls next week, but it still doesn't stop her from fantasizing what it would be like to someday dance with _him_.

* * *

In the following weeks, Richard Castle shows up on time, promptly at 5 p.m., much to Alexis's dismay, but he doesn't collect his daughter to leave. He pays Kate for the weekly lesson and then takes a seat in the waiting room with his laptop, allows his daughter a half hour, sometimes longer, with her dance instructor.

Kate notices him watching sometimes, distracted from the word document always open on his laptop, his eyes riveted to her work with Alexis. Though, not always is his gaze proud and on his daughter, sometimes she catches his eyes trained on her. It has her fumbling every once in a while, the pressure of being studied while she's dancing, by him of all people, causing her to tense up, forcing her to make quick work of calming herself back into a relaxed state before Alexis can take notice.

"Mr. Castle," she summons after one of their post class sessions, sending Alexis to the changing rooms and drawing him into the studio with the crook of a finger.

"Yes, Kate?" he grins, always using her name like a guilty pleasure that has her rolling her eyes every time.

"I don't mind if you write here," she continues on, sipping from her water bottle to cool down after a particularly intense routine with Alexis. "But try to keep your attention on your screen."

Rick arches his brow at her, steps in closer even as she steps back.

"Why, Ms. Beckett, do I make you nervous?"

Kate huffs and crosses her arms, hyper aware of the way he appreciates her body in the tight fitting, black sports top. "No, I'm just sick of turning to my left and seeing your creepy staring."

"Creepy?" he echoes with indignation. "Come on now, that's harsh. Even for you."

"Dad, don't disturb Miss Beckett," Alexis sighs, coming up behind them in her street clothes with her dance bag slung over her shoulder, and Kate has to hide a laugh behind her hand at the deepening frown carving itself into Castle's mouth.

"Yeah Castle, stop disturbing me," she mimics, her coy smile refusing to be smothered when he spins back towards her.

"You two may be dance partners, but that does not mean that ganging up on me is warranted."

"Sure it is," Kate muses, snagging her jacket from her desk chair and slipping it over her dancewear. "It's too much fun to pass up."

"Speaking of fun," Castle grumbles, casting her a glare that has her smug grin growing before turning to Alexis. "Ice cream?"

Alexis bounces on her toes, clasping her hands together in approval at the idea. "Definitely."

"Would you like to join us, Kate?"

Beckett freezes, the two sets of bright and eager blue eyes trained and waiting on her, and oh, she wants to say yes, but going for a treat with a student and her father… was that even allowed?

"I don't know if-"

"Please, Miss Beckett," Alexis begs, the elegant, mature young dancer she knows giving way to the nine year old Kate sometimes forgets she is. "Daddy always takes me to the best secret places so no one will recognize him and they always have the best ice cream."

"Yeah, Beckett, don't you want to experience the best ice cream?" Castle joins in, smirking at her over Alexis's head and if she didn't have the smallest of soft spots for him, she would have grabbed his ear and twisted it by now.

"Fine," she sighs, earning a quiet squeal from Alexis and a far too satisfied grin from her father. "Just this once."

"Lead the way, Pumpkin," Castle chuckles, holding his arm out to Kate as Alexis skips ahead towards the exit, but Kate only rolls her eyes and strides past him.

This was not a date and she refused to treat it like one.

* * *

They take the car service to Alexis's favorite ice cream shop, mostly for Kate's comfort. The place isn't too far and it's unlikely that he would be recognized, but there's always the chance and the last thing he wants, the last thing his daughter and her dance teacher wants, is to be caught sight of by a fan or a camera. The paparazzi only seemed to garner interest in him when he was spotted with a woman, no matter how innocent the interaction, and he knew for certain that Kate would not handle that scenario well.

"Well, your back leg could go a little higher," he listens to Kate muse while his daughter hangs on her teacher's every word. "But otherwise, no. You've got it down."

"Good," Alexis sighs, slumping back in the seat between the two adults, and Castle chuckles. He has no idea which dance they're talking about, but the sport has brought out the perfectionist in his baby bird. Alexis has always been determined, strived to be the best, but never to this degree. He's not sure if he should be proud or concerned.

"Don't put so much pressure on yourself," Kate murmurs before Rick can comment, patting Alexis's knee and giving his daughter a gentle but understanding smile. "You're doing an amazing job and I know it's a lot of hard work, but it's supposed to be fun too."

"Yeah, Pumpkin," Castle chimes in. "It's like with my writing. I know you hear me complain a lot, but there's nothing else I would rather be doing."

"I never complain about anything as much as you complain about your writing, Daddy," Alexis points out, earning a smirk of amusement from her teacher.

"Thank you, Alexis," he huffs, unbuckling his seatbelt as they come to a stop in front of the parlor.

It's rather plain on the outside, all brick wall and nothing more than a chalkboard with ice cream flavors listed in multicolored chalk hanging in the window. But walking inside through the single glass door, being greeted by the soft jingle of bells and the smile of the employee on the other side of the bright pink counter exposes the true potential of the place.

"Wow, I can see why it's your favorite place, Alexis," Kate murmurs from his side and he watches his daughter grin with pride and trot up to the counter.

Alexis orders her ice cream, mint chocolate chip with extra sprinkles, and Castle places his hand on the small of Kate's back when they step forward for their turn, quickly withdrawing his palm at the ripple of tension up her spine.

"Sorry, wasn't thinking," he chuckles, doing his best to play it off, to dismiss the subtle flare of her eyes flickering towards him. Besides, it had been nothing more than an innocent touch, but… oh.

Her cheeks flush the color of the strawberry ice cream on display behind the glass window of flavors and her eyes blink away the simmer of heat, the burn of an attraction she attempts to sever with the shift of her body away from him, but the whisper of it that had blossomed across his palm remains, embedded into the lines of his hand.

So he wasn't alone in that then; she felt it too.

"Castle, you go first. I'm still looking," she prompts, nodding towards the waiting attendant behind the counter, trying and failing to hide her smirk as he sputters out his order for Rocky Road.

He'd known from the moment he'd first held Kate Beckett's hand in an innocent shake of greeting that he was screwed, the proof of it unfolding in his constant appearances at the studio over the last four weeks, realizing only recently that he had stopped showing up for _only_ his daughter.

Kate places an order for coffee flavored ice cream and brushes back the bangs of Alexis's hair when his kid leans against her side, more comfortable around her dance teacher than she has been around anyone besides him and her grandmother for years now. And all he can think is that Kate Beckett is exactly what Alexis has needed and how he really wants to taste the flavor of coffee ice cream on her lips.

"Castle? You coming?" she calls and Rick blinks, lifts his gaze to the woman handing Alexis her ice cream and a napkin from the counter, prepared to follow her towards a booth near the back of the parlor.

"Of course," he quips, fishing out his wallet and handing the man at the register his card, grabbing his bowl while he waits and allowing the cold to seep into his palms, shock his senses back to reality.

But it fails to change the fact that his daughter is hopelessly smitten with her dance teacher, already attached, and she isn't the only one.

* * *

Kate does her best not to spend any more time with the Castles outside of the studio, marking up their treat for ice cream as a special occasion that isn't to be repeated. But after a month of weekly invitations that she politely declines and weak excuses that Alexis accepts without trouble but her father frowns in response to, Castle approaches her outside of the studio on a Monday morning with a mixture of trepidation and hope in his eyes that she doesn't quite understand.

"Kate?"

She pauses on the sidewalk, her keys to the building poised at the lock and her brow arching in question at the writer walking towards her, a gentle quirk to his lips and two coffees in hand.

"Hey, Rick," she greets, her smile small but true. She may be avoiding spending personal time with him, but it didn't mean her heart had stopped its ridiculous habit of fluttering every time he walked into a room, said her name. "It's eight a.m., what are you doing here?"

"I was just hoping we could talk," he answers, holding out the to go cup for her, hunching his shoulders against the cold when the wind swirls past them, whispers along his exposed neck and nips at her cheeks. "Preferably inside."

She grins and accepts the warm beverage, clutching it to her chest as she unlocks the doors and tucks her keys into the pocket of her coat.

"You have my phone number," she points out, nudging the door open with her shoulder and nodding her head for him to follow her in. "Which you take advantage of pretty frequently."

It went against her rules of keeping things strictly professional, but Castle called her rather regularly, always finding an excuse for the contact - inquiring about a concern Alexis had regarding her routine, asking for her thoughts on a chapter he just couldn't get past, for her help in plotting a fake murder.

She's started to look forward to those phone calls, hates herself for how much she enjoys the bright spots of conversation in her otherwise dark and quiet nights.

"True, but there's less of a chance for you to hang up on me if we talk in person," he grins and Kate rolls her eyes, leads him down a short hallway opposite of the girls' changing rooms, into the private space of her office. Castle's eyes roam the room, quaint but cozy with only her desk, a shelf against the wall that is packed with books and extra CDs, a row of her dance shoes along the bottom. "Hey, I didn't know you had this too."

"My desk in the studio is just for immediate access, so I don't have to leave the room when I have students here," she explains, depositing her purse into the bottom drawer of her desk and shrugging the coat from her shoulders to drape across her chair. "And I wouldn't hang up on you. Never have before."

"You say that now," he muses, shoving his hands in his pockets and letting his gaze linger on her graduate's degree from Juilliard on the wall.

"Well, what is it you need to talk about that has you fearing a dead line of connection?" she challenges, relishing silently in the impressed arch of his brow.

"Good sentence structure. Oddly arousing. Well, no, not odd at all actually-"

"Castle."

"I just came to ask if I – made you uncomfortable," he gets out, his ears turning a subtle shade of pink in the soft lamp light of her office, his lips pursed as he awaits her answer, but Kate's brow only furrows.

"Uncomfortable?" she echoes, tilting her head in confusion. "When do you think you did that?"

Castle rubs at the back of his neck and shifts in front of her desk.

"When we went out for ice cream with Alexis a few weeks ago." Oh, he's - he was still thinking about that? How she'd bristled at his touch because she couldn't handle the pleasant warmth of his hand at her back? "My kid doesn't notice anything, is just glad you came with us that once, and I'm sorry if I've been… persistent in inviting you out to dinners and whatnot with us since then-"

"Rick," she sighs, shaking her head and drifting around the side of her desk as the guilt blooms through her stomach at the misunderstanding. She had only meant to keep things platonic, refrain from taking any risks of making things personal with this family, with a little girl who looked at her with far too much light in her eyes and a man who stared at her with a different kind of illumination in his gaze. "You haven't made me uncomfortable at all."

He slumps with relief, but she can tell there are more questions to follow, more explanations to be given, so she beats him to the point.

"I just didn't want to make it a habit, you know? Didn't want to have Alexis become used to having me around so frequently outside of class," she murmurs, but by the crease that overtakes his brow this time, the downwards curve to his lips, he doesn't seem to fully understand.

"Do you not… plan to see us again after the class wraps up?"

She opens her mouth to deny it, but well, she doesn't know if he's wrong. "I – I don't know, Castle. I'm not sure if-"

"So you're planning to disappear on her too?"

Kate's jaw falls, her lips parting, and a surprising sting of hurt zigzags through her chest, but Castle is quickly waving his hands in supplication, squeezing his eyes shut. "No, that was all wrong, out of line, and it's not your responsibility – you're just her dance teacher. I'm sorry. I just meant-"

"I'm not blind, Castle," she cuts in, expelling a frustrated breath, not for him, but herself. She can easily comprehend why he's wary of her - and anyone else, really - when it comes to Alexis's sake, why he doubts her with such ease, and as much as she wishes she could, she can't really offer him a reason not to. "Alexis isn't just some throwaway kid I plan to teach for a semester and never see again, but I'm also aware of the fact that after classes wrap for this season, she likely won't see me quite as often and I don't want that to be a difficult adjustment for her."

"We could just keep seeing you every week then," he shrugs, regaining his composure, his confidence, but Kate runs a hand through her hair and purses her lips.

"You just don't get it-"

"Yes, I do. Why do you think I'm here?" he questions, stepping closer even as she crosses her arms over her chest, defenses rising with his every footstep. "I'm not blind either, Kate. I _know_ you care about my kid and I know you want to see her hurt again about as much as I do. It's why you don't want to be around me."

"Excuse me?"

"If you're even half as attracted to me as I am to you-"

"Castle, that's enough." Kate lifts a hand to stop him, silence him before she tells him to go, but he snags her fingers, forces her to feel the pulse of electricity that jolts to life at the simple touch, the frissons of it that twine through her veins and sizzle through her blood, a gentle sensation that's eager to grow.

"Every time I look at you, watch you dance… there have been so many times that you've left me without words, Kate. Not great for a man of my profession," he confesses and she nearly chokes on the strangled shard of laughter that catches in her throat. "You're smart and clever, obviously gorgeous, and you're so good to my daughter. You and these classes are the best thing that's happened to us in so long."

"Rick," she sighs, closing her eyes, unsure how they ended up here.

She's been teaching Alexis for months now, has known Castle for only one of them, but he isn't necessarily wrong in the existence of the sparks that crackle when they're together. The connection's always been there, a current between them that she's never experienced with any other man, a sensation that's only outshined by the passion that accompanies her through her dancing.

"I'm not asking you for anything, I just – I like you, Kate. A lot," he murmurs and she bites down on her bottom lip, opens her eyes to the graze of his fingertips kissing the bone of her cheek. "But regardless of whether or not you feel the same, you care more about my kid's heart, and that's… that's everything to me."

The blues of his eyes burn like flames, fierce but warm, flickering down at her with golden flecks of affection like embers in the fire.

"Your friendship is more than enough."

She squares her jaw to keep it from trembling, averts her eyes to the surface of her desk, the lone picture frame, the photo of her mother.

"I can't," she breathes, shaking her head and blinking against the sting in her eyes. "I'm not good for you, Alexis, I'm – you don't understand."

How broken she is, how she could ruin him so easily, leave him and his daughter in the wreckage of her grief. They wouldn't be the first. At her job, she was brilliant, losing herself in the art of dance, the passion of teaching it, but in her personal life… god, she's a mess. It's why she hardly has one.

"Kate," he calls softly, his hand unfurling at her cheek, thumb stroking ever so softly below her eye. "There's no way you're _not_ good for me and Alexis."

"I'm too damaged," she rasps, blinking away the burn in her eyes, refusing to let his thumb catch her tears. "After my mom… when she was murdered a few years ago, everything changed and I'm just – not good at caring about people, having people care about me."

She purses her lips again to ensure they remain steady and swallows hard, prepares for him to release her, to offer his condolences and utter lack of understanding, to join old friends, family members, Will, in exasperation.

"I can't help you if you don't want to be helped, Kate. If you can't let it go," Will had told her when he'd left her for Boston and she'd refused to come with him.

And he was right, to an extent. She couldn't simply _let go_ of her mother's murder, of needing the closure but having no idea how to get it aside from quitting a job she loves and joining the Police Academy. Or simply attempting to solve the murder on her own time, which hadn't ended well the last time.

Her father is the only one who knows, who comprehends her grief and obsession with ease, still recovering from his own fall down the rabbit hole of a liquor bottle.

But Castle surprises her, merely leans forward, drops his forehead to hers in a gesture so foreign but comforting that she hooks her fingers at his wrist, brushes her thumb to the thin skin sealed over his pulse to keep him there, make him stay.

It's been so long since she wanted someone to stick around. So much so that the thought of not seeing him and Alexis threatens to carve a piece of her heart out.

"I'm sure this is the cliff notes version, but Alexis told me a little about your mom, how you don't have one, and how dance helps you like it helps her," he murmurs. "It doesn't fix it, doesn't take away the pain I can't imagine you're living with, but it sounds like it's a part of healing in the best way you can. You're living with the grief of a tragedy, channeling some of that into your work, and helping other people cope with their own hurt. You're not damaged, Kate. You're pretty damn extraordinary."

All she has to do is tilt her chin upwards, dislodge the seal of their foreheads, to brush her lips over his, feeling her cracked heart pounding hard through the cage of her ribs, rattling her lungs as his breath stains her skin, his mouth just barely pressing against hers. It's only a whisper of a kiss, a touch of lips, gratitude she hopes he can taste in the brief connection of mouths, but it has her yearning for so much more.

"Not very hard to care about you either," he adds, his voice a low husk that heats her blood, and Kate nudges her nose to his cheek, raises her unoccupied hand to his nape.

"Friends," she decides, even as her lips rasp against the corner of his mouth while she speaks. "For now."

His smile blooms, spreading onto her lips, and she finally withdraws to lift her gaze, study the warmth in his eyes, the adoration lining his mouth, and for just a moment she lets herself believe in this, in something real and good with Castle, in the ease of heartache he and Alexis so often bring.

"Friends who kiss sometimes?" he muses, waggling his eyebrows at her, and she huffs, hides her amusement behind the waves of her hair as she shoves him away.

"Pushing it."

But she wouldn't necessarily object to working towards the kissing becoming a regular occurrence.


	2. Chapter 2

Kate spends the next couple of months meeting with Castle while Alexis is in school, usually during her lunch hours and on her days off, having coffee at nearby cafes and letting him hold her hand when they opt for walks through the parks. He kisses her sometimes, pressing his lips to the corner of her mouth before he tells her goodbye, grinning when she turns her head to snag his bottom lip with her teeth and drags him into her office for just a few extra minutes whenever she can get away with it.

She's still careful where Alexis is concerned, but she shows up at their loft at least once a week for dinner, stays a few extra hours to watch a movie most nights and lets Alexis curl into her side whenever she nestles between Kate and her dad on the couch.

"Will you keep coming over when dance classes are over?" Alexis had asked her last week, just a few days before their six month recital date, flexing her toes in Kate's lap while they sat on the living room floor of the loft, practicing stretches.

Castle had been in the kitchen, cooking dinner like always, and she had squeezed his daughter's foot, made her giggle and squirm away when she'd poked at one of the hard earned callouses on her toes with her thumb.

"Of course, silly," she'd promised without thinking, but the panic had failed to swarm her chest, spill through her guts, because she doesn't have any intentions of parting ways with the Castles, not anymore. She's far too devoted to the ten year old who'd grown up too soon and after the last few months, she's pretty sure she's in love with the writer too. "I'm not going anywhere, Lex. I enjoy hanging out with you too much and besides, if I weren't here, who would keep your dad in line?"

"Excuse me?" he'd called from the kitchen, glaring at her with a hand on his hip, a frilly apron tied across his waist that had made it difficult not to laugh each time she looked at him.

"Nothing, Betty Crocker," she'd chuckled, winking at him before returning her attention to Alexis, hearing him grumble, but she'd caught the grin on his mouth that he'd failed to hide.

"Good," Alexis had murmured, staring down at her hands for a long moment while Kate had patiently awaited for her to say what else was on her mind. "Are you and Dad… you like each other, as more than friends, right?"

Kate had swallowed her nerves, willing her skin not to flush, and nodded her head. "We do."

"Does that mean you're together?"

"Would you be okay with that?"

Alexis had rolled her eyes. "Duh."

She had laughed at that, free and relieved by the girl's approval. "Then yeah, I think it's safe to say we're together."

"Good," Alexis had repeated, a smile on her lips as she'd drawn her legs back to rise to her knees, crawling across the short space between them to wrap her arms around Kate's neck.

"Thank you, Kate."

"Nothing to thank me for," she'd replied, rubbing Alexis's back while Castle had stared on from the kitchen, met her eyes with too much in his, things she still isn't sure she's ready for.

But she wants to be. Oh, how she wants to be ready for everything he has to offer her.

Kate makes a slow lap of the studio now, during their final practice of the year, surveying each girl with a critical eye as the team performs the routine a final time before Saturday's winter recital. After six months with this group, she's proud to see that even her most challenged of students have picked up the choreography, no longer struggling their way through each dance, now performing each step with ease.

But it's her lead dancer, her star pupil in the middle of the group of six, who is currently worrying her.

"Alexis, slow your pace," Kate chides as she passes, watching Alexis follow the instruction, but still, the girl dances with tension in her spine and something like remorse in her eyes.

Beckett returns to her desk when the song comes to an end, pleased – for the most part – with the progress made and comfortable with the state her team is in.

"Well done, girls," she praises, smiling at the five young ladies beaming back at her, trying not to frown upon noticing Alexis staring crestfallen at the scuffed floor. "I've spoken with all of your parents about Saturday, but does everyone have their instruction sheet just in case?"

A brief conversation concerning the recital occurs, questions and nerves arising from her small crowd of dancers, but as parents begin to fill the lobby area, Kate sends each of them along with words of encouragement, reminding Taylor to keep her focus point during turns and ensuring that Sierra will remember her costume, until she is left with only one student.

"Alexis," she murmurs, returning to the studio to find her sitting in the middle of the floor, her knees drawn to her chest and her chin propped on the microfiber fabric of the tights stretched across her patella. "Is something wrong?"

Alexis lifts her gaze to the mirror, her blue eyes shimmering with unshed tears, and Kate takes a seat beside her.

"No," she chokes out, her small voice already cracking, the tears beginning to fall even as she furiously tries to wipe them away, the sight so heartbreaking, Kate has to resist brushing the moisture from the little girl's cheeks herself.

"Lying is bad, Lex," she chastises with a soft smile that Alexis tries and fails to return. Kate sighs, placing a calming hand on her trembling shoulder, hoping to soothe the shaking bone to no avail. "You know you can talk to me."

"It's not that," she whispers, her face beginning to crumble, the delicate skin around her eyes flaring red with the tip of her nose. "I just - I don't want to be upset that my mom isn't coming. But she promised and I - I believed her."

Alexis's silent tears escalate into gasping sobs that rob her of breath, a kind of building sorrow that Kate has never witnessed her display, and she blinks back the sting in her own eyes, pulling Alexis into her arms and allowing the girl to hide her face in her neck, wet her skin with her tears.

After becoming close with Castle, with his family, she has learned that his ex-wife, Meredith, is anything but reliable, but Rick had told her just last week that the woman had sworn to Alexis that she was flying out to New York to see her daughter's first live performance this weekend. Kate didn't know the other woman, so she had given her the benefit of the doubt, hoped on Alexis's behalf that she would stay true to her word, and now she wanted to fly to LA herself, make Meredith pay for causing her own daughter so much pain.

"Why doesn't she love me, Kate?" Alexis rasps around a new set of tears. "What did I do? What's wrong with me?"

"No, Alexis, no," Kate breathes, holding the girl tighter, rocking her back and forth like her own mother used to when she was a child. "Nothing is wrong with you, nothing. Your mother loves you, she just… loves herself more."

Alexis nods her agreement, but doesn't stop bawling, huddling in closer to Kate's chest, clinging with the arms banded around Beckett's neck.

"Why couldn't I have a mom like you?" Alexis whimpers, quiet and pitiful and so utterly heart wrenching.

And that is when Richard Castle walks in.

* * *

When Castle had entered the studio and heard no music blaring through the space, saw no immediate movement beyond the glass doors, his curiosity (and maybe a bit of his concern) had been piqued. Setting his messenger bag down on his usual seat, he climbed the three-carpeted steps that led to the studio and silently eased one of the two doors open.

Panic swarmed his stomach by instinct at the sight of Alexis crumbled and crying in Kate's lap in the middle of the barren room, the immediate assumption that she must be injured sending him tripping forward, but the closer he gets, the easier it is to see that his daughter isn't clinging to a wounded limb, isn't in any physical pain. No, she's clinging to Kate, crying softly into her shoulder.

Beckett hears him enter of course, her eyes darting to meet with his in the mirror, and the overwhelming empathy, the glistening threat of tears in her gaze, confirms it.

Alexis had told Kate about Meredith cancelling.

Kate tilts her head to the side, invitation for him to interrupt, and Rick takes a deep breath before approaching, trying to produce all of the right words and condolences for his baby bird. Alexis had sworn she was fine with her mother backing out, confessed that she even expected as much, but he knew it had cut her deep when Meredith had called him, asked to speak to Alexis, and then broke his daughter's precious heart before his eyes. Again.

"Hey Pumpkin," Castle murmurs, lowering himself to sit cross legged beside Kate on the gleaming hardwood floors. "What's going on?"

Alexis quickly wipes at her eyes, blinking rapidly to dispel the droplets still clinging to her lashes and easing out of Kate's embrace in embarrassment.

"Nothing, Daddy, I just-"

"Alexis," Kate chides under her breath and Alexis exhales, her slim ribs shuddering beneath the thin material of her leotard.

"Does this have anything to do with Mom not coming to see you this weekend?" he prompts, noticing with interest that Kate's fist clenches on her knee at the mention of Meredith. He can relate.

Alexis doesn't answer, directing her puffy gaze to her knees, but offers him a nod in return. "I know I shouldn't be upset," she mumbles, so low he has to lean forward to catch the words. "I just wish I was more important than work. I wish Mommy wanted to see me, not take me shopping or to Paris for lunch-" Kate's eyebrows rise high at that. "But just see me. She never wants to do that though."

"I know, sweetie," Castle sighs, realizing that there are no words, there will never be enough words to make Meredith's actions acceptable, especially not to the heartbroken nine year old sitting in front of him. "Mommy's just always had her priorities mixed up and she forgets how important spending time with you is, but she does love you, Alexis. I don't want you to doubt that-"

"Not like you do," Alexis argues, scratching at a snag in the shin of her tights.

"Well, maybe not in the same way…" Alexis's frown deepens. "But I'll always love you more than anyone else in the world, Pumpkin. I'm your biggest fan."

It isn't a smile, but Alexis's lips curve, her eyes growing a little lighter at the words, and then she's rising to her knees, moving forward to wrap her arms around his neck. Rick embraces her snugly, fitting her perfectly against his chest just like he always has, and while he hugs his daughter, Kate Beckett places her hand on his knee, squeezing the rounded bone and offering him a smile that soothes his aching heart.

"Does that mean I'm second biggest?" she chimes in, winking at him as Alexis withdraws to grin at Kate, wide and beaming.

"I don't know, you may have to grapple with my mother for the position," Castle muses, but Kate only shrugs, a look of feigned contemplation filling the lovely lines of her face.

"Might as well start a fan club at this point."

"Yes, good plan. Alexis has a lot of fans in her life, many who love and admire her-"

"Daddy," Alexis groans, burying her face in his shoulder while he chuckles, using his daughter's brief moment of hiding to cover Kate's hand on his knee.

"Lex, why don't you go get changed?" Kate suggests, moving to stand from the floor. "You worked hard today, no need to overextend yourself before the recital."

"But I wanted to go over my solo one more time," Alexis protests quietly, lifting her head from Castle's shoulder and pushing up from her knees so that Castle is the only one left on the floor. "I want it to be perfect."

"It will be," Kate assures her without missing a beat, and yes, he definitely adores this woman and the confidence she continues to instill within his daughter, adores the way Kate's hand cups Alexis's tear stained cheek and wipes away a stray drop with her thumb. "But if you're feeling really uncertain, maybe we could find some time near the end of the week, before Saturday."

Alexis relaxes at the idea, nodding her head in agreement. "Yes please."

"I'll talk to your dad about it. And grab a drink of water before you get dressed."

Another obedient nod and his daughter is striding out of the studio, still defeated but not so beaten down.

"Are you going to stay down there?" Kate quips, staring down at him with an arched eyebrow and a twitching lip.

Rick huffs and unfolds his legs from beneath him, forcing himself not to wince as he comes to stand beside her, following when she heads for the confined office space on the opposite side of the dance area.

"So, I'm free Friday evening if you wanted to bring Alexis in for a brief-"

"Thank you," he cuts in, but Kate doesn't lift her eyes from the planner she has opened in her hands and he sighs, reaches for her wrist. "Kate."

"God forbid I ever meet this woman, Castle," she mutters, snapping the book closed and retracting her hand from his grasp. "I might strangle her."

"And I can't say I'd actively try to stop you," he concedes, checking over his shoulder to ensure Alexis remains out of earshot.

"How can she just cancel on her own daughter like that, like it's nothing? Alexis deserves-"

"I know," he murmurs, drifting in close to quell the quiet rage simmering beneath Kate's skin with a gentle hand on her arm that has her taking a deep breath, stepping into him and knocking her forehead into his jaw. "Meredith is not the ideal mother, she never has been, and I would give anything to change that for Alexis, but I can't." Castle sighs and feels the heat of her body simmer along the edges of his as she sways into the wall of his chest, claims one of his hips with the absentminded curl of her fingers. "But she has you, Kate, and I'm not asking you to fill the role of her mother, but she looks up to you, she loves you, and I think that makes the void her mom left a little easier to deal with."

"It's not enough," she whispers, releasing him to cross her arms over her chest, clutching her elbows and glaring at their shoes.

"It's never enough when it comes to your kid," Castle agrees, watching her stiffen, but he won't take it back, not when she's been there for his daughter in the past six months more than Meredith has been for the last ten years. "But you, Kate… you are enough. For her, for - for me."

Beckett's eyes dart upwards to meet his, a deer in the headlights look if he's ever seen one, and her lips part, ready to protest or profess her own truth.

"Dad, are you ready?"

Kate's mouth snaps shut and she backs away from him, but he won't allow her to slip away so easily.

"Yeah, sweetie. I'll be right there," he calls over his shoulder, thankful when he notices Alexis's attention is on properly arranging her shoes in her dance bag while he follows Kate's retreat. "Come to dinner at our place again tonight."

"Rick," she breathes, already shaking her head, but he catches her hand, laces their fingers and grazes the so soft skin inside her wrist with his thumb.

"It'll make her evening," he coaxes, earning a glare for that, but he's not ashamed in using her weakness for his kid to convince her. "And you and I… I think it's safe to say we need to talk, don't you think?"

She sighs, but reluctantly nods her agreement. "Fine, just let me grab my stuff and lock up."

"No rush," he assures her, giving her hand a squeeze before releasing it, spinning on his heel to deliver the good news to his daughter. "Hey Pumpkin, you don't mind if we have a guest for dinner tonight, do you?"

Intrigue flickers in Alexis's eyes before understanding sets them alight as they drift to Kate, a tentative smile blooming on her lips.

"Not if it's Kate."

* * *

Alexis sticks close to her throughout their evening at the loft, sitting beside her during their dinner of Chinese food at the table, afterwards on the couch, falling asleep with her head on Kate's lap, fingers curled in the knee of her jeans. Castle carries her upstairs, cuddling his growing little girl to his chest, and Kate watches from the sofa, his words from earlier still dancing through her head like perfectly practiced choreography.

 _You're enough for her. For me._

She's never been enough for anyone before, including herself.

"Sorry she kind of clung to you tonight," Castle interrupts her musings, trotting down the last few steps with a sheepish expression claiming his face, but she shakes her head.

"It's not a problem," she dismisses. "Besides, it's not her usual. She's just had a rough day and needs the extra reassurance."

Rick sighs, nods in agreement. "Yeah, she does. Thanks for giving it to her. I know it means a lot coming from you."

She shrugs as he plops down next to her, bumping her side and dropping a kiss to the top of her head, and Kate takes advantage of his proximity, shifts to fit against his side and drop her cheek to his shoulder. It's so much easier to say what she needs to when she isn't looking at him.

"I'm not her mother," she repeats the words he'd assured her with earlier, reaching out to squeeze his thigh when he stiffens, stopping him before he can interrupt her. "I never will be. But I love her too and I'll be here for her as much as I can."

Castle deflates against her, covering her hand on his leg and slipping his fingers between the empty spaces of hers. "Kate-"

"Hush, I'm not done," she murmurs, her lips quirking as he huffs out a breath of laughter that ruffles the layers of her hair, but she sucks in a lungful of air before she continues, calms her skipping heart before it has her tripping over her own words. "I know we've talked about this a bit before, but after my mother was murdered, I closed myself off, built a wall, never wanted to hurt like that – anywhere close to that – again. I had already been enrolled in Juilliard when she was killed and she had just been so proud of me, Castle. She and my dad came to every single event, sat in every crowd, videotaped every dance I ever participated in. My mom… she was my biggest fan."

He doesn't speak, knows better, but he does tighten his grip on her hand, strokes his thumb across her knuckles.

"It's the only reason I didn't drop out, that I kept dancing. Part of me wanted – still wants, sometimes – to quit, become a detective and try to solve her case, get the justice she was robbed of, the closure my dad and I will never have." Her chest quivers, that hollow spot inside her heart throbbing, but she can't stop, even as she feels his breath hitch for her, not yet. "But every time I consider it, I remember her face in the crowd, after the shows and competitions, how happy it made her that I'd found something I loved. I think about what she wanted for me and that's the only reason I have that studio, that I turned my passion into a career, that I can't give it up."

Kate swipes at the renegade tear tripping down her cheek before it can fall. She's talked about her mom to Castle a handful of times since the first in her office, she's let him hold her when the ache of missing her mom splinters deep, threatens to crack her open, but it doesn't stop her from biting back tears every time.

"My mom and dance are all that's mattered to me, all I allowed myself to care about," she picks up, finally swallowing down her nerves and lifting her head, meeting his sad eyes and the gentle curve of his mouth. "And teaching Alexis changed that, but so has being with you."

Surprise ripples through his eyes, lightening their sorrowful shade of blue to a beautiful cerulean, and Kate leans in to cup his cheek in her palm, their noses colliding and her lashes grazing his skin before she lets her lips touch his mouth.

"I love your kid," she reaffirms, flicking her eyes from his gaze to his mouth in a habit she's learned drives him crazy. "But I love you too."

Castle lifts into her kiss, his hands ascending to cradle her face as he sips from her mouth, parts her lips with the coax of his tongue, falling into a sinuous dance with hers, a waltz of movement that has her needing to be closer, rising to slide a leg over his lap.

He moans at the weight of her body against him, the sway of her breasts brushing his chest, and she feels the tempo of his heartbeat pick up speed.

"Castle," she gasps, twining her legs around his waist when he stands without warning, pausing for only a moment and pulling back to see her face in askance.

But she already knows where they're headed and undulates her lower half against him in encouragement, impatience, humming when he darts in to kiss her mouth as he starts towards his office, his teeth at her bottom lip and her hips finding rhythm with his, eager for the ballet of their bodies in his bed.

* * *

Kate buries her face in his neck, her naked back exposed to the cool air of his bedroom, goosebumps from the cold and the sensation of his hands on her prickling along her flesh.

He shivers when she opens her mouth at his throat, tastes the sweat layered along the column of his neck, brushes a kiss to his collarbone.

"I've had many fantasies of you over the past six months, and not once did I imagine you'd be that flexible," he breathes, his lungs still trembling beneath her cheek with the unsteady rise and fall of his chest, and Kate smothers her grin against his skin before kissing the bare flesh covering his sternum and rising on her elbows.

"Not much of an imagination then, Castle," she chuckles, shifting against his side when he trails his hand up her spine, cups the nape of her neck. "That's not even half of what I could do with you in this bed."

His brow hitches almost comically, but the ripple of heat through his eyes, the blossoming darkness of lust dilating his pupils, has the laughter dying in her chest and the arousal blooming hot and fast through her system all over again.

"Show me."

Kate snags her bottom lip between her teeth, slides one of her legs over his thigh. "Now? Because I don't think you've recovered from our last round yet."

"No, not yet," he concedes, curving his hand along her outer thigh, stroking his thumb along the flex of her muscle.

Right before he flips them over.

Kate smirks up at him, cranes her neck to catch his mouth, but Castle is already lowering his, drifting down to explore the hollow of her throat with his tongue, dust his lips along the ridges of her collarbones, the slopes of her breasts.

"Castle," she gets out, her fingers twisting in his hair, her heart accelerating into an uneven arrhythmia beneath his mouth. Her entire body shudders at the trail of his hands down her sides, spanning her ribs and caressing the bones of her hips. "What-"

A mewl climbs her throat, unbidden and in time with the buck of her hips at the searing touch of his breath to the sensitive spot of her abdomen, lips just barely grazing her navel, driving her too close to the edge of combustion.

"Showing you what I can do first," he murmurs, continuing down the path of her body, unmaking her with every touch until she's spread breathless and blissful in his bed with the promise of sore muscles in the morning and the love Rick Castle sealed into her skin.


	3. Chapter 3

Kate arrives three hours early to the concert hall on the day of the recital, her mind still reeling from the last few days with the Castles, the nights spent with Rick alone, how everything's changed. How easily she's embraced it.

She devotes her time to preparing the dressing room, though, ensuring that there will be enough space for each girl and her mother to prepare.

"Kate!" Beckett lifts her head from her arranging of a clothing rack for the costumes after only fifteen minutes, feels the smile spread to her lips before she can control it at the sight of Alexis bounding through the dressing room doorway, Castle in tow with a garment bag draped over his arm, a large bag of hair products hanging from his shoulder, and a makeup kit in his hand.

"Hey, Lex," Kate chuckles, accepting the embrace Alexis delivers to her waist with a hand smoothing along his daughter's head. "And Castle, I gave you specifics on what to buy, what is-"

"Listen, both hair and makeup products are abundant in range," he states with a glower and Kate subdues her amusement. She's never seen him so frazzled.

"So you bought the entire hair and makeup sections?" she hums, absentmindedly combing her fingers through Alexis's hair, brushed and smooth, but otherwise untouched.

"Don't tease him, Kate. He was a wreck," Alexis whispers and Castle huffs from behind her.

"You're still willing to help with this?" Castle asks, his eyes tired and pleading, and Kate rolls hers, reaches out with her free hand to pat his cheek.

"Of course. Why do you think I told you guys to get here an hour early?"

"You're a godsend," he sighs, turning his head to press a kiss to her palm before moving to hang Alexis's costume on the rack next to Kate and placing the beauty supplies on the nearest table. "And you look stunning, by the way."

Kate ducks her head, the curls of her hair drifting forward to hide the heat spreading to her cheeks, grateful that Alexis has released her to take a seat in front of the vanity.

"Yeah, you look really pretty, Kate. I love your dress!" Alexis compliments with a bright smile.

Castle takes a step forward while Alexis digs through the makeup bag, neatly arranging brushes and foundations on the table before her and Kate flicks her eyes to the man in front of her, draping his broad palm along the bone of her hip, touching his lips to her cheek.

"Me too," he mumbles, the heat of his breath on her skin scorching, sending goosebumps down her spine. The dress was nothing special, a simple black cocktail dress, formal enough for a dance recital without being over the top. But she knew it hugged her curves, the thin straps of the sleeves exposing her collarbones, the slightest glimpse of cleavage.

It was enough for Castle.

Kate squeezes his biceps, returns his kiss to her cheek with a graze of her lips to his mouth before stepping out of his grasp, shooting him a look over her shoulder that promised him he'd be taking it off later, and moving to stand behind Alexis.

"Castle, pay attention. We're going to start with the hair," she announces, gathering Alexis's long, fiery locks in her fingers. "For Alexis's group dance, we're doing a typical bun, but for her solo, half of her hair will be up and half down."

To his credit, Rick pulls up a chair right beside Kate, divides his gaze between the work of her hands and the mirror, studying how she arranges Alexis's hair into the bun, where she places the pins and when she uses the hairspray. She's just began teaching him and Alexis both how to do the girl's makeup when Alexis's fellow classmates start to filter in.

"You're looking gorgeous, Pumpkin," Castle comments from beside her while Kate applies the light shade of blush to Alexis's cheeks, pausing when his daughter grins in the mirror.

The bustle of the room, though, the frenzied mothers hovering around their daughters, has Alexis sitting a little stiffer in her seat, the fingers in her lap twisting and twining with nerves.

"Hey." Kate taps her nose with the tip of the makeup brush, quirks her brow when Alexis swings her gaze away from the other girls and moms, focuses her attention on Kate once more. "Don't worry about anyone else, okay? You know I don't do favorites, but as your teacher, I can honestly say that you're the best I've ever had in my studio," she tells her quietly, watching Alexis's eyes go wide with surprise, with an overwhelming swell of gratitude. "And I know without a doubt that you're going to do so great today."

The smile that breaches her lips is hesitant, shy but brimming along the apples of her cheeks, illuminating her eyes.

"Thanks for being the best teacher ever," Alexis whispers before she takes a deep breath like Kate had always taught her, channeling her newfound confidence and returning her eyes to the mirror and the sweep of the soft brush of color along her cheeks.

Kate grins and sets the makeup tool down. "You make it easy, kid."

Castle's watching her when she plucks the eyeliner from the tabletop, concern in his gaze, unaware of the hushed words she'd exchanged with his daughter, but she shakes her head, can't discuss any of it with him here, in front of Alexis, let alone the rest of her dance team.

"Okay, hold really still for this part," Kate murmurs, tracing the lid of Alexis's eye while Castle studies the procedure in undisguised fascination, slight horror when she has to slowly draw along the waterline.

"That doesn't hurt, Pumpkin?"

"As long as I keep my eyes to the ceiling like Kate told me to, no," she chirps, waiting patiently for Kate to finish.

"Oh, Mr. Castle," Amy's mother greets, sashaying up to their little trio just as Beckett's capped the liner, coated Alexis's lashes in a thin layer of mascara. The other woman sidles up close to Castle while Kate applies the very last touch of Alexis's makeup, stroking a rosy pink lipstick to her mouth, continuing to murmur her instructions to his daughter, trying not to listen to another woman flirt with the man she's… sleeping with. Too soon to call it anything more.

Actually, no, she dismisses that line of thinking with a sharp cut of her gaze to the woman shamelessly flirting with him, because she had told Rick Castle that she loved him three nights ago and her blood begins to simmer when Linda Henderson flips her perfect blonde hair and brushes a manicured set of fingers to Castle's shoulder.

He is _hers_.

"There's an empty seat right next to me in the audience if you'd like to join me."

Kate bites her bottom lip and closes the lipstick, meets Alexis's sparkling blue eyes as she debates interjecting into the conversation.

"Don't worry, he won't sit with her," his daughter whispers, only loud enough for Kate to catch, and she rolls her eyes at the girl, expels a breath to ease her sudden bout of irritation even as Alexis smirks in return.

"That's very kind of you, Ms. Henderson. But I already have a seat, thank you," Castle returns politely and Alexis arches an eyebrow in a move she must have learned from Kate herself.

"Well, if you change your mind, I'm in row three," Linda Henderson informs him, her red lips spreading in a charming smile that Kate assumes works on most men, but Rick is pointedly looking at her as she straightens from beside Alexis.

Linda walks away and Kate steps towards him, flicks her eyes to his mouth and keeps her voice low. "Damn right you do."

Castle smirks, clasps his hands behind his back to refrain from touching her, gripping her hips and drawing her closer.

"I should probably go head to that seat now, looks like your girls are all about ready to change into costumes."

Kate nods and discretely squeezes his arm. "I'll meet you out there."

"And don't worry, I'll save your seat so you don't have to glare any more daggers into the sides of other women's heads," he teases and her cheeks begin to burn, because of course he had managed to catch that, but the warmth in his gaze tells her he's all too pleased with her silent little display of jealousy, the proof of how much she wants him all for herself, a mere glimpse of how much he means to her. Kate nudges his shoulder and he turns his attention to Alexis then, dropping to his haunches beside her chair. "Break a leg out there, baby bird."

Alexis shifts in her seat to face him, wraps her arms around her father's neck. "Thanks, Dad."

Castle pecks a kiss to the top of his daughter's head and moves to stand once more, start for the door, his fingers clashing with Kate's as he passes by, igniting sparks of embers in her fingertips. She ignores the treacherous butterflies, the incessant want that's grown tenfold, insatiable since that first night, and does her best to put it away for the next couple of hours and properly focus on the group of girls she's spent the last six months training.

The mothers slowly begin to drift out of the room after him, reluctantly leaving their daughters in Kate's hands for a final time, and once she has all six of her students dressed and ready to head backstage, Beckett takes a moment to check in with each one, ensure all are prepared to go and comfortable in their confidence levels.

"Okay girls, I'm going to lead you to the area where you'll be waiting near the curtains, and then I'm going to be in the audience, front row," Kate announces to her troop of jittery dancers. "If anyone needs something, come get me, but otherwise, please wait quietly for your turn. I know you are all going to be amazing."

Nerves mingle with excitement as she holds the dressing room door open, watching each girl file out of the room in a single line down the hall.

"And remember," she adds in a lower tone as they approach the stage area, respectful of the other groups already performing, waiting in the wings and preparing to go on. "Have fun out there."

Her students nod, but before they can completely disappear backstage, the child at the back of the line, Alexis, pauses and turns to her with her bottom lip between her teeth.

"Kate," she whispers, sucking in a shallow breath, and Beckett bends to hear her over the pounding beat of a pop song playing for the group currently on stage. "What if I mess up?"

"Then you mess up," Kate murmurs, giving Alexis's shoulder a gentle squeeze and meeting the petrified blue eyes staring back at her, hoping she can read the reassurance in hers, the conviction. "I'll be proud of you either way and so will your dad. I promise you that. But this is supposed to be fun, Alexis. When you get on that stage, dance up there like you dance with me in the studio."

A ripple of realization brightens the girl's eyes and finally, Kate witnesses the anxiety fall away to anticipation as she nods, smiles up at Kate one last time before she rushes backstage to join the rest of her class.

* * *

He spies Kate emerging through the darkness that encases the audience, striding from the door that leads backstage, and Castle's bouncing knee stills at the sight of her, striking him with the overwhelming surge of adoration and desire as she approaches. The loose waves of her hair gleam under the glow of the stage lights that catch her as she passes, her body slim and sinuous, just as gorgeous in that form fitting dress as she is in a sports bra and exercise leggings, and if this were any other event than his daughter's dance recital, he would be finding a dark, secluded place to drag her into right about now.

"You know, I'm hoping to keep this relationship private for at least a few more hours to avoid the accusations of mothers claiming special privilege for the daughter of the guy I'm dating," she murmurs when she takes her seat beside him, inconspicuously glancing around before crossing her legs and hooking her ankle over his calf, the heel of her stiletto a pleasant point of contact against his muscle.

"I'm trying," he whines, covering the bare skin of her knee, stroking her patella with his thumb even as she bats at him with a spare program she must have grabbed along the way. "But you didn't stay last night and it's been nearly 24 hours since I made love to you, haven't even kissed you today-"

"Castle," she huffs, but her lips are trembling with amusement, her eyes glimmering gold in the darkness.

"Plus, that jealousy thing was really hot so I-"

"I'm begging you to shut up."

"I want you to hear you begging for other things," he husks, can't help himself, and oh, that gets to her, has her covering the hand on his knee and squeezing hard.

" _Later_."

Heat zips like a livewire through his veins, but he forces himself to snap out of it, focus on what's truly important tonight.

"How's Alexis?"

"Terrified of making a mistake," she sighs, loosening her grip on his hand, her palm a soft, pleasant weight over his knuckles. "But I told her that she'll be great. And I know she will, but I also reminded her that even if she does mess up, it doesn't change how proud we are of her."

Castle stares at the profile of her face for a long moment, watching the current dance occurring on stage – tiny little girls dressed as ducks, shaking their bright yellow tail feathers to the beat – and realizes in damn near horror that in the last three days, since everything had been so beautifully changed, he hadn't said it back.

He's so in love with this woman, with her mind and her body, her care and concern for his daughter, and he'd been so sure that he'd spoken the words back to her that first night, but looking at her now, awe spreading like sunlight through his chest, it strikes him that he had yet to say them aloud.

He's breathed them into her skin, traced them against her mouth with his tongue, mumbled them into her hair when they've laid tangled in his bed and half asleep, but never spoken them clearly, never said them with the clarity she deserves.

"Kate-"

"Oh, they're next," she breathes, clutching his hand with anxious excitement spilling through her eyes, tugging her mouth into a proud smile as her class is announced.

"Kate," he says almost urgently, just – needing to say it, needing her to know-

She turns her head to him, her eyebrows arched with impatience, but he holds her gaze as if the rest of the world has gone momentarily still around them, professes the words to her just seconds before his daughter takes the stage.

"I love you too."

* * *

She doesn't care if anyone sees her holding his hand throughout the recital, doesn't care if anyone notices the overwhelming pride that leaks into her features when Alexis takes the stage for her solo, if they hear her cheering as loud as Castle does afterwards. Too happy to care about any of it.

There's a brief awards ceremony at the end of the recital, an excuse for the sponsors to hand out a ton of pretty participation trophies, and Kate's class surprises her with the first place award for their age group. Alexis's solo earns her a second place trophy, her small stumble through the middle costing her a few extra points that Kate knows his daughter will agonize over, but for the girl's first solo ever, Beckett feels nothing but proud.

She has to abandon him for a while to congratulate her girls, rewarding each and every one with praise, speaking with each parent about the process of enrolling for classes again in the spring, but once her huddle of six has dwindled down to one red haired girl still in her simple but sparkling white skirt and leotard from her solo, Kate holds her arms out to Alexis Castle and grins when his daughter barrels into her.

"You did so good," Kate whispers, cupping Alexis's beaming face, her swollen cheeks, in her palms. "You were like a pro up there."

Alexis withdraws only a step to stare up at her, her smile unwavering but the slightest flicker of uncertainty appearing in her bright blue eyes. "Even though I messed up my solo?"

"Messed up? Hardly," Kate dismisses with a shake of her head. "For your first time? That was incredible work up there, Alexis."

"Can I keep training?" Alexis inquires, bouncing on her toes. "I loved it up there, Kate. I never want to stop dancing, I want to be like you!"

Oh, and she has to bite her tongue, refrain from fiercely protesting, expressing just how much the idea of Alexis turning out like her terrifies her. She wants so much better for this girl, so much more.

"If you want to keep dancing, I'd be honored to keep teaching you," Kate says instead, laughing as Alexis hugs her again, thin arms tight around her waist, trophy digging into her back and the medal around Alexis's neck pressing against her stomach.

Kate manages to catch the trophy from Alexis's surprised fingers before she's swept up from behind, squealing as Castle spins her around.

"Dad," she giggles, clutching her arms around his neck. "Put me down!"

He complies, but it doesn't stop him from bending to Alexis's height, gushing over her performance and applauding every step he witnessed her take on that stage, causing Alexis's to blush, but it's worth it to see the smile on his daughter's face, to know that Alexis actually feels proud of herself for a change.

"Ready to go out for a fancy dinner to celebrate your winnings?" Castle inquires, standing with a wince as his knees pop, shooting a glare at Kate when she chuckles at him for it, their ongoing joke about his age.

"Yeah!" Alexis exclaims, reaching for his hand, for Kate's next before abruptly pausing, her fingers barely curled around only one of Kate's, and glancing up to her with the question hopeful in her eyes. The same shade of hope echoed in his. "Are you coming with us, Kate?"

She flexes her fingers to properly encase the full set of Alexis's small hand, her gaze ascending to Castle's over his daughter's head. "Where else would I be?"

* * *

Kate helped Alexis remove all of her makeup after dinner, dessert, and a trip to a flower shop Castle frequented ("Because the night cannot end without me presenting my two favorite dancers with bouquets of flowers," he'd insisted). She'd brushed the growing length of the girl's hair, sitting behind Alexis on her bed and gently combing through every tangle until Alexis is swaying, her head jerking with the effort of staying awake.

"There," she'd whispered, setting the comb down on the nightstand and running her fingers through Alexis's smooth locks. "All ready for bed."

"Today was the best day," Alexis had sighed sleepily, leaning back against Kate's chest. "I wish it didn't have to end."

"I know, but there will be more," Kate had promised, banding an arm around Alexis to keep her from tilting sideways.

"With all of us?" Alexis had yawned, blinking in an effort to stay awake, losing the fight when Kate began brushing her fingers through the girl's bangs, debating on the right answer, the best answer to give. The truth.

"I'd like to think so," she'd admitted, resting her cheek against the top of Alexis's head, listening to the slowing intake and exhale of breath.

"Good," Alexis had slurred, her body growing heavy in Kate's arm.

"Uh oh, exhaustion's overtaking my prima ballerina," Castle had chuckled, walking through the bedroom doorway with warmth in his smile and affection in his eyes as he'd approached the bed, helped Kate ease Alexis under the covers.

They'd tucked her in together, far too domesticate for what Kate had ever prepared for, but not… wrong, it hadn't felt wrong at all. It'd felt like something she could learn to do on a regular basis, a piece of her new normal.

"Night, Pumpkin. Sweet dreams," Castle had whispered, pressing a kiss to her forehead before standing from his daughter's bedside.

"Love you, Daddy," Alexis had mumbled, her eyes remaining closed. "Love you, Kate."

Castle had glanced to her in uncertainty, but she hadn't hesitated to respond in unison with him.

"Love you too."

She'd followed him outside of Alexis's bedroom after that, let Castle take her to his, let him touch every inch of her, undo her piece by piece, remake her in the same instance with the reverence of his hands, the worship of his mouth, the love he expelled with every breath.

Alexis had been right, it'd been the best day, and she hadn't been ready for it to end either, couldn't stop replaying it in her mind. It's how she ends up in his living room hours after he'd finally fallen asleep curled around her, draped in his button down and staring out one of the floor to ceiling windows, studying the sea of city lights glittering below.

"Kate?" he calls, padding out of his office when she turns her head, her lips twitching at the sight, the odd angles where his hair sticks up, the confused, sleepy little boy pout to his lips. "What're you doing up?"

She shrugs, waits for him to join her, and rests her back to the wall of his chest, covers the arms that lace around her waist with her own, holding him there, wishing to stay like this.

It's the first time she's wanted to stay anywhere with anyone for longer than a night.

"Just couldn't sleep," she murmurs, touching her forehead to his jaw.

He hums, grazes his lips to the line of her hair. "Is everything okay?"

"Better than," she affirms, sliding her fingers to fit within the spaces between his, welcoming the pleasant flutter of her heart for once. She embraces it all tonight, lets the silly butterflies and the swell of her heart run wild and free, lets her love for him flourish and bloom through her chest. "I'm… so happy, Castle."

It comes out like a surprise, a statement she hadn't necessarily meant to say aloud, but he sighs his approval of the voiced thought with a kiss to her lips.

"So am I, Kate. More than you know."

Her smile blossoms and she shifts in his arms, turns her back to the glow of the city, the darkness of the sky, and seals the front of her body to his, feels the cadence of his heartbeat, the warmth of his skin beneath the t-shirt he must have tugged on before coming to find her. She'll ridicule herself for all of this in the morning, for the blatant show of vulnerability, the exposure of just how deep she is with this man, this family, but in this moment, all she wants is to savor, to share it with him, ensure that he sees it all.

Because this dance she's found with him, this effortless rhythm they move to and the seamless choreography that comes so naturally, without a single step of practice, is unquestionably the best performance she's ever taken part in. She never wants it to end, never wants the music to stop, not with him.

Kate rises on the tips of her toes to dust a kiss to his lips, traces her tongue to the curve of his smile before she opens her mouth to speak. "Hey Castle?"

His hands drift down her sides in response, fitting them perfectly along her waist, and she cradles the hard lines of his jawbone in her palms, allows her eyes to flutter shut as his forehead lowers to its home against hers, and begins to sway in the moonlight of his living room with his body following along.

"Dance with me."

Anyone else would have looked at her as if she was insane, she's sure of it, but Castle's eyes peel open, lashes tangling with hers, and the clear blue certainty she meets the second she opens hers is all the reassurance she needs to prove that he doesn't, that he comprehends her request with ease.

"Thought you'd never ask."


End file.
